Note that AMD Radeon HD 7900 users should keep using
the 8.921.2 RC11 driver found here (the 12.2 preview
does not supported the AMD Radeon HD 7900 Series).

Feature highlights of the AMD Catalyst 12.1
driver:

AMD HD3D technology support enhancement

- Enables support for AMD HD3D technology in
conjunction with AMD CrossFireX configurations
- Delivers a new Stereo 3D mode over HDMI 1.4a
connections - 1080p at 30Hz is now enabled on
supported displays.

- AMD Catalyst 12.1 Preview driver enables users to
create per application profiles to individually
control 3D and CrossFireX settings for Direct3D
applications
- Be sure to select the "Restore Factory Defaults"
option under the Catalyst Control Center Preferences
menu before using the new application profiles feature
- this ensures there are no compatibility issues
between previous drivers and the new AMD Catalyst 12.1
Preview driver with regards to application
profiles

This release of AMD Catalyst Linux introduces support
for the following new operating systems:

- SLED 11 SP2 early look support
- Ubuntu 11.10 production level support

Feature highlights of the AMD Catalyst 12.2
driver:

AMD Eyefinity 2.1 technology enhancements

- Additional resolution support: Users can now choose
from a larger set of resolutions when running AMD
Eyefinity
- Dynamic Configuration Changes: Switching between
different display configurations will occur
automatically when physically plugging/un-plugging
displays
- HydraVision enhancements: The Windows Task bar can
now be moved and resized based on users preference
- Profile Manager improvements: Increased support for
Display Groups (including 5?1) and Extended
configurations within the Profile Manager